SQL & PL/SQL :: Pass More Characters To In Mode Parameter Using Procedure

I am trying to pass many characters to the in mode parameter using procedure , but i am getting the below error.

ORA-06550:
PLS-00172: string literal too long

CREATE TABLE USR_DETAILS
(
LOAD_ID NUMBER NOT NULL,
LOAD_DATE DATE,
USER_VALUE VARCHAR2(4000 BYTE),
USERID VARCHAR2(4000 BYTE)
)
insert into user_details values('1','2/10/2011','PROD1','USER1');
insert into user_details values('2','2/10/2011','PROD2','USER2');
[code]......

I have written the code as below...

Procedure concept :

Here i will seperate the strings(input parameters) using comma(,) symbol . Here users may pass more than 5000 characters to single in mode parameter, so i have tried with clob datatype but no luck.

CREATE OR REPLACE procedure user_details_proc (user_value1 IN varchar2,
user_value2 IN varchar2,
user_value3 IN varchar2,
user_value4 IN varchar2,
user_value5 IN varchar2,
userid IN varchar2
) as
[code].......